RFR (S): 8237777 "Dumping core ..." is shown despite claiming that "# No core dump will be written."

[gerard ziemski]

On 4/24/20 11:44 PM, David Holmes wrote:
> On 25/04/2020 4:02 am, gerard ziemski wrote:
>>
>>
>> On 4/23/20 7:55 PM, David Holmes wrote:
>>
>> [trimmed]
>>
>>> Given that the "Dumping core ..." is only shown in non-product 
>>> builds I think we are way over-thinking/engineering this. We have:
>>>
>>>   if (dump_core) {
>>>   ...
>>> #ifndef PRODUCT
>>>     ...
>>>     out.print_raw_cr("Dumping core ...");
>>> #endif
>>>     ::abort(); // dump core
>>>   }
>>>
>>> so lets just change one line:
>>>
>>>     out.print_raw_cr("Requesting a core dump if possible ...");
>>>
>>> otherwise you need one boolean to control whether we call abort vs 
>>> exit, and a second boolean to control what we print.
>>>
>>> Or change that one line to:
>>>
>>>     out.print_raw_cr("Calling ::abort() ...");
>>
>> Making sure we do not mess up the core creation logic is paramount, 
>> so I like your suggestion to keep it simple, but perhaps we can take 
>> it one small step further and just not bother with that message at all?
>>
>> Maybe we should simply remove the line:
>>
>>     out.print_raw_cr("Dumping core ...");
>>
>> completely? After all, we print lots of core dumping related info 
>> anyhow.
>
> We've been printing
>
>   Current thread is xxx
>   Dumping core ...
>
> to the default output stream in non-product builds since day one of 
> this code - literally. Why only non-product and why only for when 
> dump_core is true I have no idea. The whole thing seems somewhat 
> superfluous. I'd suggest either tweaking the second line, or removing 
> it all, rather than just deleting the second line (which gives some 
> additional context to the first).

I gave it some thought, looked at a few Linux distros, and personally 
I'd like to see both of those lines to go away. We already print the 
crashed thread info in the hs_err crash log, even before we get to those 
2 lines, so we're not risking loosing the "current thread" info.

bug:https://bugs.openjdk.java.net/browse/JDK-8237777
webrev:http://cr.openjdk.java.net/~gziemski/8237777_rev3
tests:  tested with Mach5 tier-hs1,2,3,4,5

Lastly, I believe that there is still much we can do to improve the core 
file related messages, but that will be covered in JDK-8243196


cheers